Measles

Aka: Measles, Rubeola, Morbilli, First Viral Exanthem of childhood, Red Measles

1. Etiology
   1. Morbillivirus: Briareus morbillorum
2. Pathophysiology
   1. Incubation: 14 days (from exposure to rash onset)
      1. Range: 7-18 days (rarely up to 21 days)
   2. Transmission
      1. Droplets of nasopharyngeal secretions
      2. Highly contagious
         1. Affects 90% of susceptible household contacts
3. Epidemiology
   1. Sporadic outbreaks in teenagers and young adults
   2. Incidence
      1. U.S. Cases in 1941: 894,000 cases
      2. U.S. Cases in 2000: 86 cases
4. Symptoms
   1. Prodrome (precedes the rash by 2-3 days)
      1. Classic "3 C's"
         1. Severe Cough (dry, hacking)
         2. Coryza
         3. Conjunctivitis
      2. Fever
      3. Malaise
      4. Irritability
      5. Photophobia
   2. Koplik's Spots in Mouth (3-4 days after prodrome)
   3. Rash spreads from forehead to trunk (1-2 days later)
5. Signs
   1. Koplik Spots (pathognomonic)
      1. Grayish-white sand-like dots
      2. Slight, reddish areolae that may be hemorrhagic
      3. Often opposite upper first and second molars
      4. My spread to involve any of Buccal mucosa
   2. Fever (Onset with rash)
   3. Blotchy erythematous Morbilliform rash
      1. Discrete red-brown Macules blanch with pressure
      2. Begins on forehead
      3. Spreads to face and neck, behind ears
      4. Spreads to trunk and entire body
   4. Cervical Lymphadenopathy
6. Course
   1. Severity related to extent and confluence of the rash
   2. When rash reaches feet, clinical improvement has begun
7. Complications
   1. Early
      1. Severe disease with dehydration
      2. Pneumonitis
      3. Pneumonia (3% of young adults)
         1. Includes Interstitial Giant Cell
      4. Otitis Media
      5. Hepatitis
      6. Glomerulonephritis
      7. Myocarditis
      8. Encephalitis (1 per 1000 Measles cases)
         1. Onset 4-7 days after rash
         2. Mortality: 10%
   2. Late
      1. Subacute sclerosing panencephalitis (SSPE)
         1. Incidence: 8.5 cases per 1 million Measles cases
   3. Overall Mortality: 1-2 deaths per 1000 Measles cases
8. Labs
   1. Complete Blood Count
      1. Leukopenia during prodrome
         1. Lymphocytes <2000 associated with poor prognosis
   2. Respiratory secretions with multinucleated giant cells
   3. Immunofluorescent staining of respiratory cells
   4. Serology
9. Prevention
   1. Active Immunization at 12-15 months
      1. Contraindications: Immunocompromised
   2. Passive Immunization post exposure
      1. Dose
         1. Gamma globulin: 0.25 ml/kg (MAX 15 ml)
      2. Indications
         1. Children under age 3 years
         2. Pregnant women
         3. Tuberculosis
         4. Immunocompromised patients